The pulmonary vascular resistance (PVR) is elevated to some extent in all patients with congenital diaphragmatic hernia (CDH). In those with severely elevated PVR closure or restriction of a previously patent ductus arteriosus (PDA) can precipitate hemodynamic compromise secondary to acute heart failure. Maintaining ductal patency in this subset of patients is not a well-established therapeutic strategy. This report reviews the potential utility of maintaining ductal patency by discussing the pathophysiology and reviewing the published literature.